1. Field of Invention
This invention generally relates to pallets and other devices used for goods and material handling, supporting, transporting and the like. More specifically, this invention relates to corrugated fiberboard pallets that are lightweight, inexpensive to manufacture, readily disposable, easy to recycle and able to be made water resistant.
2. Description of the Related Art
For many years, pallets have been used for the handling, supporting and transporting, for example, of goods and material. Traditionally, such pallets have been made from wood. Wooden pallets have wooden runners upon which boards are nailed or stapled to produce a deck on which goods are stacked or otherwise placed. The wooden runners elevate the deck above a floor or other supporting surface. This enables the tines of a forklift truck or other transport device to be inserted beneath the deck. Sometimes, the runners are notched to provide four-way entry of a forklift or a pallet jack.
With the ever-increasing cost of lumber, wooden pallets have become expensive. The estimated dollar volume of new pallets produced in the United States in 1991, alone, was $4.4 billion for approximately 541 million new pallets produced. In order to justify their cost, wooden pallets must be used over and over again.
Recent ecological efforts have placed an emphasis on reducing consumption of raw lumber. Such efforts also have placed an emphasis on the ability to recycle any products originally made from wood or lumber, for instance, as the raw material. However, due to their construction of heavy wood and nails, traditional wooden pallets are not readily recyclable and/or biodegradable.
Recent estimates show that of the pallets produced in the United States in 1991, sixty percent were of the warehouse or returnable variety, while forty percent were of the expendable or single use variety. Accordingly, approximately 216 million of the wooden pallets produced in 1991 were shipped only one-way within the United States or overseas. It is estimated that 50 million pallets are shipped out of the country, one-way, each year.
Wooden pallets themselves are also heavy, so that even a load of unloaded wooden pallets is not easily transported or handled. Rather, the weight of such pallets limits the number which may be stacked by a forklift or transported by a pallet jack. These limitations increase the floor space required for storage, which, in warehouses, is very expensive. Such expenses are passed on to the end user or consumer. Heavy wooden pallets also are limited in the amount of weight they may carry. Such payload weight should be limited by the products being carried, rather than by the carrying device.
A few pallet manufacturers have substituted less expensive or lighter weight materials either in whole or in part for wood, and have produced pallets which by reason of their cost may be used more readily on a disposable or one-trip basis. For example, decks made of corrugated paperboard have been substituted for the traditional boards. Also, runners formed from plastics or foam in a honeycomb configuration have taken the place of traditional wooden runners. Pallets so made cost considerably less than the traditional wooden pallets. Moreover, such pallets are considerably lighter than wooden pallets, and thus, are much easier to handle.
Even though paperboard pallets of the foregoing construction have advantages over traditional wooden pallets, they may not possess the strength of wooden pallets, either in compression or in shear. In this regard, a pallet that utilizes plastic or foam for its supporting legs may collapse if shifted laterally over a floor while the runners are in contact with the floor. This sometimes occurs when forklift operators try to manipulate the pallets laterally over a floor. This is known as side-shifting.
Other attempts have been made to manufacture pallets entirely of corrugated cardboard. However, to date, such pallets have had limited strength, since manufacturers have compromised strength for reduction in weight. Weight of cardboard pallets can be reduced by using elements of minimal thickness, such as those made of a single layer of corrugated cardboard. However, such a decrease in weight also significantly decreases structural integrity. This is disadvantageous.
Accordingly, a need has arisen for a corrugated fiberboard pallet that is lightweight and constructed from an inexpensive and recyclable material, yet possesses substantial strength, approaching or exceeding that of traditional wooden pallets.